rustc will use rust-lld by default on x86_64-unknown-linux-gnu on nightly to significantly reduce linking times.
Good. But a lot of us do this already:
[target.x86_64-unknown-linux-gnu]
linker = "clang" # for mold
rustflags = ["-c", "link-arg=-fuse-ld=/usr/bin/mold"]
[target.x86_64-unknown-linux-musl]
rustflags = ["-Z", "gcc-ld=lld"]